Corner insert for a packaging tray



FIG. 1 is a top, front, right side perspective view of a corner insert for a packaging tray showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof, the right side being a mirror image of FIG. 3;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The dotted lines are for environment only and are not part of the claimed design. 

The ornamental design for a corner insert for a packaging tray, as shown and described. 